Polished diamond prices have been rising steadily in the first half of 2018, according to analysis on the RapNet Diamond Index (RAPI™), and this trend continued in June. Having risen by 3.4% in H1 2018, the index for 1-carat diamonds climbed another 0.8% in June. According to the RAPI, 0.30 ct. stones have continued to rise more sharply than any other category, gaining 3.1% in June and 9.7% since January.
Rapaport News commented, "Diamond market sentiment was positive in June after the Las Vegas shows demonstrated robust US jewelry demand. Suppliers held polished prices firm amid shortages in some categories and as high rough prices squeezed manufacturing profit margins." The United States and China continue to drive market demand. The diamond news group said, "Larger brands and innovative independents working to improve the buying experience in-store and online are gaining market share. Jewelers that are unable to change the way they engage with customers are losing out." They add that manufacturers and dealers are aligning their inventory with retailers’ needs, resulting in slightly lower stock levels than this time last year. Additionally, greater efficiency is a greater reliance on memo are also cited as reasons for declining inventory. Rough prices have continued to rise, squeezing margins in the midstream.